This invention relates to devices for cutting stone, rock, coal or other hard materials. More particularly this invention relates to stonecutters employing chain-like cutting heads.
The cutting of limestone, rock, coal and other hard materials, using chain sawing devices has been known for many years. These devices are normally designed to include a continuous chain having stone cutting links based along its outer edge. The chain, in turn, rotates about a drive sprocket and one or more additional sprockets. However, one of the major problems with these devices has been the extreme wear to which the teeth on the sprockets, particularly the drive sprocket, are subject.
Various sprocket designs have been suggested which allow for the rotation or removal of particular worn or defective sprocket teeth. For example, in U.S. Pat. No. 3,381,354, a sprocket is described whereby the teeth may simply be reversed to provide another driving face. See also U.S. Pat. No. 1,643,472. In U.S. Pat. No. 1,630,313, the replacement of sprocket teeth is provided, but no specific method for accomplishing this step is disclosed. See also U.S. Pat. No. 4,089,406. Document No. 2073, dated June 15, 1867, discloses some sort of drive device, but it is not clear whether this device is designed for use with a chain, and there is no description of the composition of the materials used.
In view of the serious and costly problems encountered with prior art stonecutting devices, it is an object of this invention to prepare devices which are not readily subject to sprocket wear.
It is another object of this invention to prepare sprockets which may be used repeatedly and for long periods of time without undue wear or malfunction.
Yet another object of this invention is to prepare stonecutting devices utilizing sprocket teeth which may readily be replaced without replacement of the entire sprocket.
These and other objectives are obtained using the device disclosed in this invention.